Mobile communication system and method for the requesting of positive delivery reports from individual group members

ABSTRACT

Disclosed is a mobile communication system and a method for requesting a disposition notification from each group member for an IM message. In the method, a sender can request desired group members for a disposition notification for an IM (Instant Messaging) message in a group messaging service. To this end, the sender on the transmission side constructs an IM message in such a manner as to include information on the group members designated by the sender, and then transmits the constructed IM message to an IM server. After receiving the IM message from the sender, the IM server generates IM messages corresponding to the group members based on the information included in the received IM message, and then transmits the generated IM messages to the group members, respectively. Accordingly, only the group members that have received the IM messages can generate their own reports, and then transmit the generated reports to the sender. By doing this, the sender can receive the disposition notification only from the desired group members.

TECHNICAL FIELD

The present invention relates to a mobile communication system and amethod for providing a messaging service, and more particularly to amobile communication system and a method, by which it is possible torequest group members of a group messaging service for a dispositionnotification for a message when transmitting the message to the groupmembers.

BACKGROUND ART

Now, the OMA (Open Mobile Alliance) maintains a standard specificationnamed SIMPLE IM (Instant Messaging based on Session Initiation Protocolfor Instant Messaging and Presence Leverage Extensions) service. Thisinstant messaging technology enables groups to transmit/receive messagesto/from each other by using groups defined by each user of an instantmessage. In this case, a service supported by the above instantmessaging technology refers to a group messaging service. As describedabove, the group messaging service is based on the SIMPLE IM service inwhich multiple users can simultaneously transmit/receive messagesto/from each other according to the Session Initiation Protocol (SIP).

In the SIMPLE IM (Instant Messaging) service, after transmitting an IMmessage, a user on a transmission side often desires to know whether auser on a reception side has actually received the IM message or hasread the received IM message. In this case, the user on the transmissionside may request the user on the reception side or an IM server on thereception side for Instant Message Disposition Notification (IMDN) whichis a processing state of the IM message transmitted from the user on thetransmission side. The detailed contents of the IMDN can be checked in areference document [draft-ietf-simple-imdn-07]. According to thisreference document, the IMDN, which the user on the transmission sidecan request, are largely classified into three types. The three typesare processing reports, delivery reports, and read reports.

First, the processing report indicates that the IM message transmittedby the user on the transmission side has been normally processed by theIM sever. This processing report has 4 attributes. A “processed”attribute indicates that the IM message is normally processed. A“stored” attribute indicates that the IM message is stored in a networkfor the later delivery of the IM message. An “error” attribute indicatesthat the result of IM message processing cannot be checked. A“forbidden” attribute indicates that the processing report is notallowed.

The delivery report indicates whether the IM message has been deliveredto a relevant terminal on the reception side. The delivery reports aredistinguished by a positive delivery and a negative delivery. Thisdelivery report has 4 attributes. A “delivered” attribute indicates thatthe IM message is delivered to the relevant terminal on the receptionside. A “failed” attribute indicates that the IM message cannot bedelivered to the relevant terminal on the reception side. An “error”attribute indicates that it is not possible to check whether the IMmessage has been delivered to the relevant terminal on the receptionside. A “forbidden” attribute indicates that the delivery report is notallowed.

The read report indicates whether the user on the reception side haschecked or has reproduced the IM message. The read report has 3attributes. A “read” attribute indicates that the user on the receptionside has checked or has reproduced the IM message. An “error” attributeindicates that it is not possible to know whether the user on thereception side has checked the IM message. A “forbidden” attributeindicates that the read report is not allowed.

As described above, a network on the reception side or the terminal onthe reception side, which has received the IMDN request, may transmitthe notifications of several types back to a network on the transmissionside or the terminal on the transmission side by using the processingreport, the delivery report, the read report and so on, depending on theresults of IM message processing. Further, a header field, a messageformat and other details, which are newly defined for expressing theIMDN request and a response to the IMDN request, can be checked in thereference document [draft-ietf-simple-imdn-07].

DISCLOSURE Technical Problem

In the group messaging service as described above, any user can requestthe other remaining users for IMDNs when transmitting IM messages to theother remaining users who are participating in the group messaging.However, in a current system, the IM messages transmitted from a senderare delivered to all members excluding the sender, who are participatingin the group messaging. Therefore, if the sender expresses his/herintention for IMDN requests in the IM messages, the other remainingterminals or users that have received Accordingly, they generate theirown reports, and then transmit the generated reports back to the networkon the transmission side or the terminal on the transmission side.

The existing method as described above is not efficient from thesender's viewpoint as well as from the networks' viewpoint. When theother remaining users, who have received the IM messages, generate theirown reports by the IMDN requests of the sender and then transmit thegenerated reports to the sender, much load may be applied to thenetwork, and then may cause many network failures. Moreover, when thesender receives the reports from the other remaining recipients eventhough he/she is interested in only the result of IM message dispositionfrom a particular recipient, the sender may think as if the reports outof his/her interest are spam messages.

Technical Solution

Therefore, the present invention has been made in view of theabove-mentioned problems, and the present invention provides a mobilecommunication system and a method, by which a sender can request groupmembers of a group messaging service for a disposition notification fora message when transmitting the message to the group members.

In accordance with an aspect of the present invention, there is provideda method for requesting a disposition notification from each groupmember for an IM message by a transmission client in a mobilecommunication system including the transmission client, an InstantMessaging (IM) server and multiple target clients, the method including:generating an IM message including information designating at least twotarget clients, from which reports to the IM message are intended to bereceived among the multiple target clients, and report types for whicheach of the at least two target clients is intended to be requested;transmitting the generated IM message to the IM server; and receivingreports corresponding to the report types requested for each of the atleast two target clients from each of the at least two target clientsthrough the IM server.

In accordance with another aspect of the present invention, there isprovided a method for providing a disposition notification from eachgroup member for an IM message by an Instant Messaging (IM) server in amobile communication system including a transmission client, the IMserver and multiple target clients, the method including: receiving anIM message from the transmission client; determining whether thereceived IM message includes information designating at least two targetclients, from which reports to the IM message are intended to bereceived among the multiple target clients, and report types for whicheach of the at least two target clients is intended to be requested;re-generating an IM message from the received IM message for each of theat least two target clients, and transmitting the re-generated IMmessage; receiving reports corresponding to the report types requestedfor each of the at least two target clients from each of the at leasttwo target clients through the IM server; and transmitting the receivedreports to the transmission client.

In accordance with another aspect of the present invention, there isprovided a transmission client for requesting a disposition notificationfrom each group member for an IM message in a mobile communicationsystem including the transmission client, an Instant Messaging (IM)server and multiple target clients, the transmission client including: amessage generator for generating an IM message including informationdesignating at least two target clients, from which reports to the IMmessage are intended to be received among the multiple target clients,and report types for which each of the at least two target clients isintended to be requested; and a transmitter/receiver for transmittingthe generated IM message to the IM server, and receiving reportscorresponding to the report types requested for each of the at least twotarget clients from each of the at least two target clients through theIM server.

In accordance with another aspect of the present invention, there isprovided an Instant Messaging (IM) server for providing a dispositionnotification from each group member for an IM message in a mobilecommunication system including a transmission client, the IM server andmultiple target clients, the IM server including: a controller fordetermining whether an IM message received from the transmission clientincludes information designating at least two target clients, from whichreports to the IM message are intended to be received among the multipletarget clients, and report types for which each of the at least twotarget clients is intended to be requested, and re-generating an IMmessage from the received IM message for each of the at least two targetclients; and a transmitter/receiver for receiving the IM message fromthe transmission client, transmitting the re-generated IM message toeach of the at least two target clients, receiving reports correspondingto the report types requested for each of the at least two targetclients from each of the at least two target clients in response to thetransmission of the re-generated IM message, and transmitting thereceived reports to the transmission client.

Advantageous Effects

According to the present invention, when a sender requests IMDN (InstantMessage Disposition Notification) for an IM message transmitted byhim/herself, by improving the existing method for requesting all groupmembers excluding the sender for IMDN, the sender can request onlydesired group members for the IMDN. Therefore, the sender can beprevented from receiving undesired reports. As a result, it is possibleto reduce the burden of charging caused when the sender and eachrecipient transmit/receive an unnecessary report to/from each other.Further, by preventing an unnecessary waste of network resources, thenetwork resources can be efficiently utilized, so that it is possible topromote the quality improvement of an IM service.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the presentinvention will become more apparent from the following detaileddescription when taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is an illustrative view showing a syntax in aDisposition-Notification header field according to an exemplaryembodiment of the present invention;

FIG. 2 is a signal flow diagram showing a process for transmitting andreceiving messages between a sender and each target recipient accordingto an exemplary embodiment of the present invention;

FIG. 3 is an illustrative view showing the case of directly expressingtarget recipients according to an exemplary embodiment of the presentinvention;

FIG. 4 is an illustrative view showing the case of indirectly expressingtarget recipients according to an exemplary embodiment of the presentinvention; and

FIG. 5 is a flowchart showing the operation of an IM server on atransmission side according to an exemplary embodiment of the presentinvention.

BEST MODE Mode for Invention

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings. Itshould be noted that the same or equivalent elements are denoted by thesame reference numerals throughout the accompanying drawings. Also,detailed descriptions of well-known functions and structuresincorporated herein, which may unnecessarily obscure the subject matterof the present invention, will be omitted.

The present invention proposes a method, by which a sender can requestdesired group members for a disposition notification for an IM (InstantMessaging) message in a group messaging service. To this end, accordingto the present invention, the sender on the transmission side constructsan IM message in such a manner as to include information on the groupmembers designated by the sender, and then transmits the constructed IMmessage to an IM server. After receiving the IM message from the sender,the IM server generates IM messages corresponding to the group membersbased on the information included in the received IM message, and thentransmits the generated IM messages to the group members, respectively.Accordingly, only the group members that have received the IM messagescan generate their own reports, and then transmit the generated reportsto the sender. By doing this, the sender can receive the dispositionnotification only from the desired group members.

Before describing the present invention, the reference document[draft-ietf-simple-imdn-07], to which the present invention refers, willbe briefly explained. This reference document[draft-ietf-simple-imdn-07] provides a mechanism, by which a sender canrequest IMDN, and to this end, newly defines several CPIM (CommonProfile for Instant Messaging) headers. One of the newly-defined CPIMheaders is a Disposition-Notification header field. TheDisposition-Notification header field is used to inform recipients ofwhat types of reports the sender requests.

In the present invention, the sender uses the Disposition-Notificationheader field to designate target recipients among group members, and tothis end, a new parameter is defined in the Disposition-Notificationheader field. The use of the Disposition-Notification header field andthe newly-defined parameter therein for designating target recipientswill be specifically described with reference to FIG. 1.

FIG. 1 is an illustrative view showing a syntax in theDisposition-Notification header field according to an exemplaryembodiment of the present invention. According to the syntax illustratedin FIG. 1, the Disposition-Notification header field may have fieldvalues corresponding to an optional number of parameters requested amongnegative-delivery, positive-delivery, processing, and read. When theDisposition-Notification header field has at least two field values, theat least two field values are separated by commas. A ‘generic-param’ maybe located right after each of the at least two field values separatedby the commas, and is separated from each of the at least two fieldvalues by a semicolon. According to the preset invention, a newparameter 200, which is used to indicate target recipients according toIMDN request from the sender, is defined by the ‘generic-param.’

As illustrated in FIG. 1, the newly-defined parameter 200 named ‘target’may have at least one URI (Uniform Resource Identifier) value. When thetarget parameter has at least two URI values, the at least two URIvalues must be separated by delimiters. In the present invention, commasmay be used as the delimiters. However, when the use of the commas asthe delimiters is determined to be inappropriate, the commas may bereplaced by another more appropriate delimiter.

By using the target parameter defined as a new parameter as describedabove, when transmitting an IM message including IMDN request to groupmembers, any sender, who is participating in group messaging, can selectgroup members at the sender's disposal as well as all group members, andcan request only the group members selected by the sender for IMDN.

Hereinafter, an operation between the elements of a mobile communicationsystem based on the group messaging service will be described withreference to FIG. 2. FIG. 2 is a signal flow diagram showing a processfor transmitting and receiving messages between the sender and eachtarget recipient according to an exemplary embodiment of the presentinvention. In FIG. 2, member 1 is a transmission client, and members 2,3 and 4 are target clients designated by the transmission client. Inorder to help understanding of the present invention, members 1, 2, 3and 4 are called Alice, Ann, Bob and Tom, respectively. Also, forconvenience of the following description, a transmission client terminalis called sender, and target client terminals are called targetrecipients.

The transmission client terminal includes: a message generator forgenerating an IM message including both information designating at leasttwo target client terminals, from which the transmission client terminalintends to receive reports to the IM message among the multiple targetclient terminals, and report types, which the transmission clientterminal intends to request according to the designated target clientterminals; and a transmitter/receiver for transmitting the generated IMmessage to an IM server, and receiving reports corresponding to thereport types, which the transmission client terminal has requestedaccording to the target client terminals, from the designated targetclient terminals through the IM server.

Also, the IM server includes: a controller for determining whether theIM message received from the transmission client terminal includes theinformation designating the at least two target client terminals, fromwhich the transmission client terminal intends to receive the reports tothe IM message among the multiple target client terminals, and thereport types, which the transmission client terminal intends to requestaccording to the designated target client terminals, and re-generatingIM messages according to the designated target clients from the receivedIM message; and a transmitter/receiver for receiving the IM message fromthe transmission client terminal, transmitting the re-generated IMmessages to the designated target client terminals, receiving thereports corresponding to the report types, which the transmission clientterminal has requested according to the target client terminals, fromthe at least two designated target client terminals in response to thetransmission of the re-generated IM messages, and transmitting thereceived reports to the transmission client terminal.

First, when intending to receive the notifications of whether the IMmessages have been received, the results of IM message disposition,etc., the transmission client terminal corresponding to member 1 10constructs an IM message in such a manner as to include an IMDN requestby standards determined by [draft-ietf-simple-imdn-07]. Particularly,according to an exemplary embodiment of the present invention, thetransmission client terminal constructs an IM message includinginformation on target recipients in order to designate desired groupmembers. To this end, “target” parameters newly defined in theDisposition-Notification header field is used as illustrated in FIG. 1.

When the IM message designating the target recipients has been generatedas described above, in step 100, the transmission client terminaltransmits the generated IM message to the IM server 20. At this time,the IM message transmitted to the IM server 20 includes target parameterinformation designating the target recipients according to the requestedreport types. Therefore, the IM server 20 must request each targetrecipient for reports as the sender intends by analyzing the targetparameters included in the IM message.

In this regard, examples of constructing IM messages transmitted to theIM server 20 are shown in FIGS. 3 and 4. FIG. 3 is an illustrative viewshowing the case of directly expressing target recipients according toan exemplary embodiment of the present invention. FIG. 4 is anillustrative view showing the case of indirectly expressing targetrecipients according to an exemplary embodiment of the presentinvention.

FIG. 3 illustrates a body part of the IM message generated by using thetarget parameters when the sender requests a read report and a positivedelivery report to a text message such as “Hello world” whiletransmitting the text message. For example, when the sender requestsBob, member 3 for only a read report, requests Ann, member 2 for a readreport and a positive delivery report, and requests Tom, member 4 for noreports, information on the target recipients may be expressed asillustrated in FIG. 3. For reference, the body part of the IM messageincluding the IMDN request is expressed as contents in the CPIM format.

In FIG. 3, a Disposition-Notification header field 300 has ‘read’ and‘positive-delivery’ as field values, and has a target parameter relatedto each field value. A target parameter related to ‘read’ has Bob'saddress as a parameter value. A target parameter related to‘positive-delivery’ has Bob's address and Ann's address as parametervalues. On the other hand, since there are no reports for which Tom hasbeen requested, Tom's address corresponds to no target parameter value.As illustrated in FIG. 3, the target parameters of theDisposition-Notification header field can directly represent URIs(Uniform Resource Identifiers) which are the addresses of the targetrecipients according to the relevant report request.

Meanwhile, differently from FIG. 3, the target parameters may indirectlyrepresent the URIs which are the addresses of the target recipients asillustrated in FIG. 4. In this case, a URI-List and IDs indicating theURI-List are used.

Specifically, the URIs of the target recipients according to the IMDNrequest are entered in the URI-List (i.e. an XML document), and theURI-List including the URIs of the target recipients is inserted into abody part of the IM message. In this case, the target parameters haveIDs as values which indicate the inserted URI-List. FIG. 4 shows anexample of expressing the target recipients according to the IMDNrequest by using the URI-List and the IDs on the URI-List. In FIG. 4,the URI-List representing Ann's URI and Bob's URI is inserted into abody part 410 of a CPIM domain in the IM message. Also, a targetparameter, which is subordinate to ‘read’ corresponding to a field valueof a Disposition-Notification header field 400, has a pointer 405 as aparameter value which indicates the URI-List. The pointer 405 to thisURI-List is assigned to the target parameter, and indicates a content-ID415 of the body part 410 in the CPIM domain.

As described above, FIGS. 3 and 4 illustrate two syntaxes for requestingAnn and Bob for their read reports. In FIG. 4, a target parameter, whichis subordinate to ‘positive-delivery’ corresponding to a field value ofthe Disposition-Notification header field 400, can also indirectlyrepresent target recipients according to the request for positivedelivery reports as in the case of the field value ‘read’. However, whenthe number of the target recipients is singular, a URI-List of a person,who is intended to be indirectly expressed, must be inserted into thebody part of the CPIM domain in the IM message, so that the entire sizeof the IM message unnecessarily increases. Therefore, in this case, itis more efficient to directly express the target recipients asillustrated in FIG. 3.

The IM message constructed as illustrated in FIG. 3 or in FIG. 4 istransmitted to the IM server 20. When receiving the IM message, the IMserver 20 first determines whether the IM message includes targetparameter information. When the determination result shows that the IMmessage includes target parameter information, in step 105, the IMserver 20 re-generates IM messages to be transmitted to members based onthe target parameter information.

Specifically, in step 110, the IM server 20 generates an IM message,which requests Ann, member 2 30 for a read report and a positivedelivery report, based on the target recipient information shown in FIG.3 or in FIG. 4, and transmits the generated IM message to Ann. In step115, the IM server 20 generates an IM message, which requests Bob,member 3 40 for a read report, and transmits the generated IM message toBob. In step 120, the IM server 20 generates an IM message, whichrequests Tom, member 4 50 for no reports, and transmits the generated IMmessage to Tom. At this time, it goes without saying that all there-generated IM messages must include the text “Hello world”corresponding to user data which Alice, member 1 10 intends to transmit.Also, on the assumption that all group members are in the same serviceprovider area, a separate IM server is not required for each targetrecipient as illustrated in FIG. 2, and the IM server 20 on thetransmission side directly transmits the re-generated IM messages to thetarget recipients. Otherwise, in order to transmit the re-generated IMmessages to the members 30, 40 and 50, after transmitting there-generated IM messages to an IM server on the reception side, the IMserer 20 transmits the re-generated IM messages to the members 30, 40and 50 through the IM server on the reception side, respectively.

Meanwhile, the above operation process is also equally applied to thecase where the Disposition-Notification header field has multiple fieldvalues and has target parameters related to some of the multiple fieldvalues. For example, it is assumed that a Disposition-Notificationheader field has ‘positive-delivery’ and ‘read’ as field values and hasa target parameter related to ‘read’ but does not have a targetparameter related to ‘positive-delivery.’ In this case, each of thetarget recipients designated by the target parameter is only requestedfor a read report. On the other hand, each of the recipients (i.e. allgroup members) of the IM messages is requested for a positive deliveryreport to which a target parameter is not related. In other words, afield value in the Disposition-Notification header field, to which atarget parameter is not related, is processed in the existing method,and each of the recipients of the IM messages is requested for a reportindicated by a relevant field value of the Disposition-Notificationheader field.

Meanwhile, when receiving the IM message including the report request,by accepting the report request, each target recipient generates arequested report, and then transmits the generated report back to thesender.

At this time, even after a target recipient rejects the report requestfrom the sender, the target recipient generates a relevant report, andtransmits the generated report back to the sender. However, in thiscase, the report from the recipient includes contents such that thetarget recipient has rejected the report requested by the sender insteadof the requested message state information or the requested messagedisposition information. Further details of the above description followthe reference document [draft-ietf-simple-imdn-07].

In step 110, Ann, member 2 30 has been requested for the read report andthe positive delivery report. Therefore, in step 125, Ann transmits thepositive delivery report to the IM server 20, and in step 130, transmitsthe read report to the IM server 20. Then, the IM server 20, as in step135, combines the received read and positive delivery reports into asingle report, and transmits the single report to member 1 10, thesender. In step 115, Bob, member 3 40 has been requested for a readreport. Therefore, in step 140, Bob transmits the read report to the IMserver 20. Then, the IM server 20, in step 145, transmits the readreport to member 1 10, the sender. As described above, when receiving areport from each target recipient, the IM server 20 on the transmissionside transmits the received report to the sender. At this time, the IMserver 20 may transmit the received report to the sender immediatelywhen receiving the report. Otherwise, after waiting for a predeterminedtime period, the IM server 20 may combine the reports, which have beenreceived within the predetermined time period, into a single report, andthen transmit the single report to the sender.

Hereinafter, the operation of the IM server 20 on the transmission sidewill be described in detail with reference to FIG. 5. FIG. 5 is aflowchart showing the operation of the IM server on the transmissionside according to an exemplary embodiment of the present invention.

Referring to FIG. 5, in step 500, the IM server 20 determines whether anIM message has been received. When the determination result shows thatIM message has been received, the IM server 20 determines in step 505whether the IM message includes an IMDN request. Specifically, the IMserver 20 determines whether the IM message includes a request for adisposition notification from each target recipient for the IM message.Whether the IM message includes the request can be determined by whetherthe IM message includes a Disposition-Notification header field.Therefore, the IM message including the IMDN request implies that the IMmessage includes the Disposition-Notification header field.

When the IM message does not include the IMDN request, the IM server 20,in step 510, processes the IM message in the existing method. Namely,the IM server 20 copies the IM message a number of times equal to thenumber of all group members, and transmits the copied IM message to eachgroup member. To this end, the IM server 20 can change the content of arecipient address field of each copied IM message to an IM address ofeach group member.

On the other hand, when the IM message includes the IMDN request, the IMserver 20, in step 515, analyzes a Disposition-Notification header.Namely, the IM server 20 analyzes a Disposition-Notification headerfield. In step 520, the IM server 20 determines based on the analysisresult whether the Disposition-Notification header field includes targetparameter information. When the determination result shows that theDisposition-Notification header field does not include the targetparameter information, the IM server 20 proceeds to step 510. In step510, the IM server 20 processes the IM message, which does not includethe target parameter information, in the existing method for processingan IM message including an IMDN request. Therefore, all the recipients(i.e. all the group members) of the IM messages are requested for theIMDN which the sender has requested.

On the other hand, when the determination result shows that theDisposition-Notification header field includes the target parameterinformation, the IM server 20 proceeds to step 525. In step 525, the IMserver 20 determines whether values of target parameters are in aURL-List form. Specifically, the IM server 20 determines whether thevalues of the target parameters represent URI values corresponding tothe IM addresses of the target recipients or indicate a URI-Listincluded in a body part of the IM message.

When the values of the target parameters indicate the URI-List includedin the body part of the IM message, the IM server 20, in step 530,generates an IM message including a report request designated for eachof the members having addresses on the URI-List. Therefore, the IM sever20 includes, in an IM message to be transmitted to each of the IMaddresses represented in the URI-List, a report request indicated by afield value of a Disposition-Notification header field related to atarget parameter for each target recipient.

On the other hand, when the values of the target parameters are not inthe URI-List form (i.e. when the values of the target parameters are theURI values of the target recipients), the IM server 20, in step 535,generates an IM message including a report request designated for eachof the members having the URI values as their addresses. Therefore, theIM server 20 includes, in an IM message to be transmitted to each targetrecipient having a relevant URI value, a report request indicated by afield value of the Disposition-Notification header field related to atarget parameter for each target recipient.

After generating the IM messages according to the target recipientsthrough the process as described above, the IM server 20, in step 540,transmits the generated IM messages to group members corresponding tothe target recipients, respectively. At this time, if the targetrecipients and the sender exist in the same network area, the IM server20 on the transmission side directly transmits the IM messages to thetarget recipients. Otherwise, the IM server 20 on the transmission sidetransmits IM messages to target recipients through an IM server on thereception side which provides group messaging services to group members.According to the present invention as described above, after designatingdesired group members among group members, a sender receives adisposition notification only from the designated group members.Therefore, it is possible to promote the quality improvement of an IMservice.

INDUSTRIAL APPLICABILITY

While the invention has been shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various embodiments or modified embodiments ofthe present invention may be made therein without departing from thespirit and scope of the invention. Therefore, the spirit and scope ofthe present invention must be defined not by the descried embodimentsthereof but by the appended claims and equivalents of the appendedclaims.

1-15. (canceled)
 16. A method for requesting a disposition notificationfrom each group member for an Instant Messaging (IM) message by atransmission client in a mobile communication system including thetransmission client, an IM server and a plurality of target clients, themethod comprising: generating an IM message including informationdesignating at least two target clients among the plurality of targetclients, which are requested to report reception of the IM message, andreport types for the reception of the IM message; transmitting thegenerated IM message to the IM server; and receiving reportscorresponding to the report types requested from each of the at leasttwo target clients through the IM server.
 17. The method as claimed inclaim 16, wherein the report types include at least one of a read reportindicating whether the IM message has been checked, a delivery reportindicating whether the IM message has been transmitted to each of the atleast two target clients, and a processing report indicating whether theIM message has been normally processed by the IM server.
 18. The methodas claimed in claim 16, further comprising receiving reportscorresponding to the report types requested from each of the at leasttwo target clients by re-generating an IM message from the received IMmessage for each of the at least two target clients by the IM server andtransmitting the re-generated IM message to each of the at least twotarget clients.
 19. The method as claimed in claim 16, wherein theinformation designating the at least two target clients is inserted intoa disposition-notification header field in the IM message.
 20. Themethod as claimed in claim 16, wherein the information designating theat least two target clients is represented as a URI value of each of theat least two target clients by a target parameter defined in adisposition-notification header field of the IM message.
 21. A methodfor providing a disposition notification from each group member for anInstant Messaging (IM) message by an IM server in a mobile communicationsystem including a transmission client, the IM server and a plurality oftarget clients, the method comprising: receiving an IM message from thetransmission client; determining whether the received IM messageincludes information designating at least two target clients among theplurality of target clients, which are requested to report reception ofthe IM message, and report types for the reception of the IM message;re-generating an IM message from the received IM message for each of theat least two target clients, and transmitting the re-generated IMmessage; receiving reports corresponding to the report types requestedfrom each of the at least two target clients; and transmitting thereceived reports to the transmission client.
 22. The method as claimedin claim 21, wherein the report types include at least one of a readreport indicating whether the IM message has been checked, a deliveryreport indicating whether the IM message has been transmitted to each ofthe at least two target clients, and a processing report indicatingwhether the IM message has been normally processed by the IM server. 23.The method as claimed in claim 21, wherein the information designatingthe at least two target clients is inserted into adisposition-notification header field in the IM message.
 24. The methodas claimed in claim 21, wherein the information designating the at leasttwo target clients is represented as a URI value of each of the at leasttwo target clients by a target parameter defined in adisposition-notification header field of the IM message.
 25. The methodas claimed in claim 21, wherein, in transmitting the received reports tothe transmission client, whenever reports corresponding to the reporttypes requested for each of the at least two target clients arereceived, the received reports are transmitted to the transmissionclient.
 26. The method as claimed in claim 21, wherein, in transmittingthe received reports to the transmission client, after receiving reportscorresponding to the report types requested for each of the at least twotarget clients, after a predetermined time period combining the receivedreports into a single report and transmitting the single report to thetransmission client.
 27. A transmission client for requesting adisposition notification from each group member for an Instant Messaging(IM) message in a mobile communication system including the transmissionclient, an IM server and a plurality of target clients, the transmissionclient comprising: a message generator for generating an IM messageincluding information designating at least two target clients among theplurality of target clients, which are requested to report reception ofthe IM message, and report types for the reception of the IM message;and a transmitter/receiver for transmitting the generated IM message tothe IM server, and receiving reports corresponding to the report typesrequested from each of the at least two target clients.
 28. Thetransmission client as claimed in claim 27, wherein the report typesinclude at least one of a read report indicating whether the IM messagehas been checked, a delivery report indicating whether the IM messagehas been transmitted to each of the at least two target clients, and aprocessing report indicating whether the IM message has been normallyprocessed by the IM server.
 29. An Instant Messaging (IM) server forproviding a disposition notification from each group member for an IMmessage in a mobile communication system including a transmissionclient, the IM server and a plurality of target clients, the IM servercomprising: a controller for determining whether an IM message receivedfrom the transmission client includes information designating at leasttwo target clients among the plurality of target clients, which arerequested to report reception of the IM message, and report types forreception of the IM message, and re-generating an IM message from thereceived IM message for each of the at least two target clients; and atransmitter/receiver for receiving the IM message from the transmissionclient, transmitting the re-generated IM message to each of the at leasttwo target clients, receiving reports corresponding to the report typesrequested from each of the at least two target clients in response tothe transmission of the re-generated IM message, and transmitting thereceived reports to the transmission client.
 30. The IM server asclaimed in claim 29, wherein the report types include at least one of aread report indicating whether the IM message has been checked, adelivery report indicating whether the IM message has been transmittedto each of the at least two target clients, and a processing reportindicating whether the IM message has been normally processed by the IMserver.